It's a double for 'Hangover'

Heather Graham, Justin Bartha join Todd Phillips' cast

Heather Graham and Justin Bartha have joined the cast of Warner Bros. and Legendary Pictures' "The Hangover," being directed by Todd Phillips.

The movie begins production this week in Las Vegas.

The story revolves around three buddies, played by Bradley Cooper, Ed Helms and Zach Galifianakis, who lose their best friend (Bartha) at his Caesars Palace bachelor party just 40 hours before his wedding. The trio must attempt to retrace all their bad decisions from the night before and figure out where things went wrong.

Graham, repped by UTA and Affirmative Entertainment, will play a Vegas local who crosses paths with the guys and might know more about the groom than she lets on.

Bartha, repped by Endeavor, is best known for the "National Treasure" movies. He next appears in the ensemble shorts film "New York, I Love You."